This invention relates to a nut cracking device and in particular to a device that cracks hard shell nuts such as macadamia nuts and filberts, utilizing the novel splitting technique described in our U.S. Pat. No. 4,793,248, issued Dec. 27, 1988, entitled, Nut Shelling Machine. In the referenced patent, there was described an automated shelling machine for splitting the shells of hard shell nuts, particularly macadamia nuts which have a smooth, hard, round shell.
Conventional devices that employ impact or high compression forces typically shatter the shell and damage the kernel. Furthermore, when a brittle shell of a nut of this type shatters, there are many small pieces of shell that must be separated from the meat, much of which may be broken. Since it is always desirable to crack the shell from a nut leaving the kernel whole, the design of the nut shelling machine of the referenced patent utilizes a technique where a specially designed blade on a roller cuts into the thick outer shell of the macadamia nut and splits the shell, generally in two pieces. In the preferred embodiment of the referenced shelling machine the nut is entrapped between rollers where opposed blades engage the nut. This type of complex machine, while suitable for factory shelling of nuts is not suitable for hand cracking of nuts where the complexity and expense of the device must be kept at a minimum.
In the embodiments of the hand cracking device of this invention, the principal of splitting a nut with a shear or wedge action as opposed to impact or compression cracking is utilized in a modified form. The cracking mechanism in the hand cracking device is again of a shell splitting type and utilizes a unique blade mechanism that is common to several different embodiments of the invention that may be designed to appeal to the ultimate user.